Feldman: What would Rams defense look like under Ryan?

ST. LOUIS, Mo. (FootballStL) -- As reports surfaced Friday night regarding the interest the Rams were apparently showing in Rob Ryan (one incorrectly stating it was a done deal) it raised the question of what such a defense would look like here with him in charge.

Ryan was fired by Dallas following a season in which the Cowboys ranked 19th in total defense while giving up 355 yards per game. They also were 24th in the league in scoring defense while surrendering 25 points a game.

In this case, Cowboys owner and GM Jerry Jones was simply looking for a sacrificial lamb to justify making changes following an 8-8 season where they failed to make the postseason.

But if the Rams are indeed interested in bringing in Rob Ryan to be their next defensive coordinator, I'm skeptical with how the Rams personnel would fit what Ryan likes to do.

You see...the Cowboys ran a 3-4. That's where there's three down linemen and four linebackers. The Rams run a 4-3 defense. Obviously, the opposite. Those two schemes could not possibly be more different. Someone who plays end in a 3-4 usually can't play end in a 4-3. Same goes for defensive tackle, unless it's a massive 320+ pound nose tackle. The linebackers are different as well. Both inside and outside.

In a 3-4, the primary pass rushers are the outside linebackers where in a 4-3 it's the two ends, like Robert Quinn and Chris Long. Guys like them have to be big enough to take on offensive tackles at the line of scrimmage and stuff the run without getting blown off the ball but also fast enough to get around them to put pressure on the quarterback. They're usually in the 265 pound range (Long is 270 while Quinn is 264).

3-4 ends, meanwhile, need to be big enough to take on offensive tackles and stuff the run but they don't have as much help along the line. Their job is primarily holding the point of contact at the line of scrimmage to allow the four linebackers to flow to the ball and rush the quarterback. Therefore, they need to be even bigger. As in, the 285-290 pound range. Would it be fair to ask Quinn or Long to do that? Especially given the fact they are pass rushers first?

No.

How about putting them at outside linebacker? Well...they're a different breed as well. Rob Ryan's two pass rushing OLB's were DeMarcus Ware and Anthony Spencer. They both weighed around 250-255 pounds. At that position you are in coverage almost as much as you're getting after the QB. You have to be better in space to stay with running backs out of the backfield or chasing tight ends down the field.

Do you think it'd be fair to ask Quinn and/or Long to do that?

No.

The list goes on. James Laurinaitis (6'2", 250 lbs) isn't quite as big as someone who would typically play inside linebacker in a 3-4 either.

I would think the evidence is pretty clear that the Rams cannot and should not try and transition their defense to a 3-4. So, would Ryan be able to come in here and run a 4-3 defense? That'd be the only way to make this work.

There's no evidence to suggest he can. But there's also no evidence to suggest that he cannot.

Rob Ryan loves to be aggressive and has a pretty good history of being successful as a defensive coordinator. And it's too early to know if he'll end up being the guy here in St. Louis.

It'd just seem like an odd fit given his history and the Rams current personnel.